Created By : awnish

Reviewed By : Rajashekhar Valipishetty

Last Updated : Apr 10, 2023

Take the help of the Solenoid Magnetic Field Calculator tool to get the magnetic field inside a solenoid. Just you have to provide current, length and number of turns details in the input fields of the calculator and hit the calculate button to get the magnetic field as soon as possible.

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Number of turns(N):

Steps to Find Magnetic Field Inside a Solenoid

Have a look at the detailed steps on how to calculate the magnetic field inside a solenoid efoortlessly. Go through the principles, rules and follow them carefull.

  • Obtain the amount of current flowing through solenoid, number of turns and length of the solenoid.
  • Multiply the number of turns with the vaccum permeability constant and current.
  • Divide the product by the solenoid length to check the magnetic field.

Solenoid Magnetic Field Formula

The solenoid is a wire that is tightly wound in a long, thin coil. If current is flowing through wire, then a magnetic field is around it.

The magnetic field outside an infinite length solenoid is zero and costant for inside solenoid. The formula to calculate the magnetic field inside a siolenoid is along the lines.

B = μoIN / L


B is the magnetic fiels of the solenoid

I is the current flowing through a solenoid

μo is vaccum permeability and its value is 1.26×10-7 Tm/A

N is the number of turns

L is the length of the solenoid


Question: A solenoid with 25 turns carries a current of 15 A and the length is 32 cm. What is the magnetic field inside the coil?


Given that

Number of turns N = 25

Current I = 15 A

Length L = 32 cm = 0.32 m

Magnetic field of the solenoid formula is B = μoIN / L

B = (1.26×10-7 x 15 x 25)/0.32

= (472.5 x 10-7)/0.32

= 1476.5 x 10-7

Therefore, the magnetic field inside the solenoid is 1476.5 x 10-7 A.

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Frequently Asked Questions on Solenoid Magnetic Field Calculator

1. What is the magnetic field inside a solenoid?

The solenoid is a coil of wire that is designed to generate a strong magnetic field within the coil. It is a type of electromagnet whose intention is to produce controlled magnetic field.

2. What is the magnetic field in a solenoid formula?

The magnetic field inside a solenoid is directly proportional to the applied current and number of turns per unit length. Its formula is B = μoIN / L.

3. Does the length of the solenoid affect the magnetic field?

Yes, the solenoid length affects the magnetic field. As the magnetic field is inversely proportional to the coil length, the greater solenoid length means a lesser magnetic field.

4. A solenoid of diameter 20 cm has a magnetic field of 3.5 x 10-5 N/A m. If it has 250 turns, find the current flowing through it?

Given that,

Number of turns N = 250

Length of the solenoid L = 0.2 m

Magnetic field B = 3.5 x 10-5 N/A m

The solenoid magnetic field formula is B = μoIN /L

I = BL/(μoN)

= (3.5 x 10-5 x 0.2)/(1.26×10-7 x 250)

= (0.7 x 10-5/(315 x 10-7)

= 222 mA

Therefore, the current flowing through the solenoid is 222 mA.